1: Basic Organization of the Nervous System

Question 1

Neurons

Answer 1

the major functional unit of the nervous system

Question 2

Neuroganglia

Answer 2

cells that play an important tole in supporting the neurons

Question 3

Nerve

Answer 3

a bundle of axons held together by connective tissue

Question 4

Cell body

Answer 4

integrated information, synthesizes and processes proteins for the neuron

Question 5

What are 2 other names for a cell body?

Answer 5

1. soma
2. perikaryon

Question 6

Dendrites

Answer 6

numerous short processes that receive information from other cells, contain receptors for neurotransmitters

Question 7

Axon

Answer 7

moves materials from cell body to synaptic terminals, carry action potentials, may be insulated with myelin

Question 8

Myelin

Answer 8

covering on the axon, not always present

Question 9

Axon hillock

Answer 9

cone-shaped segment of cell body, part of “trigger zone” where action potentials are generated

Question 10

Presynaptic termianls

Answer 10

collection of fine branches at distal end of axon

Question 11

Synapse

Answer 11

specialized junction that allows neurons to communicate with other cells

Question 12

Myelin functions

Answer 12

1. increase speed of conduction
2. protection
3. insulation
4. repair neurons

Question 13

Axons with larger diameter have ____ conduction velocity

Answer 13

faster

Question 14

White matter

Answer 14

regions are axons with myelin sheats

Question 15

White matter in CNS

Answer 15

nerve tracts in spinal cord and brain

Question 16

White matter in PNS

Answer 16

myelinated axons of peripheral nerves

Question 17

Gray matter

Answer 17

regions are where the cell bodies and dendrites of neurons collect

Question 18

Gray matter in CNS

Answer 18

in the cortex and named nuclei of the SC and brain

Question 19

Gray matter in PNS

Answer 19

cell bodies congregate in regions called ganglia

Question 20

Polarity of primary sensory neurons

Answer 20

most are unipolar

Question 21

Polarity of special sensory neurons

Answer 21

most are bipolar

Question 22

Polarity of motor neurons

Answer 22

most are mulipolar

Question 23

3 subdivisions of PNS

Answer 23

1. somatic
2. autonomic
3. enteric

Question 24

Plexuses

Answer 24

network of nerves

Question 25

Where are cell bodies of lower motor neurons in the SC?

Answer 25

ventral horn

Question 26

Where are cell bodies of autonomic motor neurons in the SC?

Answer 26

lateral horn

Question 27

Where are cell bodies of somatic sensory neurons?

Answer 27

dorsal root ganglia and dorsal horn of the SC

Question 28

What is another name for a mixed spinal nerve?

Answer 28

peripheral nerve

Question 29

Mixed spinal nerve

Answer 29

bundle of nerve axons

Question 30

Somatic nervous system

Answer 30

voluntary portion of the nervous system

Question 31

What are the neurons of the somatic nervous system called?

Answer 31

lower motor neurons

Question 32

Autonomic nervous system

Answer 32

involuntary portion of the nervous system

Question 33

What are the 2 divisions of the autonomic nervous system?

Answer 33

1. Sympathetic - "fight or flight" 2. Parasympathetic - "rest and digest"

Question 34

Enteric nervous system

Answer 34

control the digestive tract independently of the CNS through local reflexes

Question 35

What cells produce myelin sheaths?

Answer 35

lemmocytes